The present invention relates to convertible dual container systems, and more particularly to systems where a fluid stored in one container is periodically required for use in a second container.
Dual container systems may find use in a wide variety of applications. For example, in systems requiring the segregated storage of two liquids for a period of time before mixing, blending, etc., a dual container system is a necessity. Additionally, some systems may require a second liquid periodically to regenerate the contents of a container through which a first process liquid has been flowing. These systems may include beds of ion exchange resins or filter media which periodically become exhausted. A particular application of dual container systems is in the field of domestic water softening.
Household water softeners utilizing ion exchange typically include a resin tank, through which hard water is passed and exchange of "hard" ions of calcium and magnesium for "soft" sodium ions takes place, and a brine tank. After a period of operation the ion exchange resin in the resin tank needs to be regenerated to remove accumulated hardness ions and to replenish softness ions. This is accomplished by passing a salt solution from the brine tank through the resin bed.
The regeneration cycle typically lasts about an hour and needs to be done, on the average, about every other day. More frequent regenerations are required during periods of heavy water usage. With each regeneration cycle, a new charge of brine solution is required. Typically, household water softening systems have provided for storage of dry salt pellets above the level of brine solution in the brine tank sufficient for providing brine solution for relatively long periods of time.
Prior art household water softening systems have been constructed either with the brine and resin tanks in a side-by-side relationship or with the resin tank fitted within the brine tank. Typical of the side-by-side structure is Rose, U.S. Pat. No. Re. 25,979. This type of structure permits maximum storage capacity for salt and eliminates the need for frequently refilling the brine tank with salt. However, the side-by-side structure requires a relatively large amount of floor space which may not always be available in smaller homes or apartments.
Placing the resin tank within the brine tank as shown by Miller, U.S. Pat. No. 3,285,418, and Prior et al., U.S. Pat. No. 3,891,552, conserves floor space, but greatly reduces the volume of usable salt storage space within the brine tank and necessitates frequent refilling thereof with salt. Additionally, neither the prior art side-by-side tanks nor the resin tank within brine tank systems were adapted to convert from one configuration to the other if the need arose, such as for example, if the water conditioning system was moved to a different location. Moreover, distributors of domestic water softening systems had to stock both separate types of systems because convertibility from one to the other was not possible.
Accordingly, the need exists in the art for a dual container system which is easily convertible to either a side-by-side or tank within a tank configuration as the need arises and which, because of its adaptability, can be installed in a wide variety of locations.